Numerous homeowners and businesses are looking for ways to reduce their electrical consumption for a variety of reasons. Some people are reducing the amount of electrical consumption to save money, while others are doing so to conserve energy, thereby reducing pollution associated with power production. A known way of achieving a reduction in electrical consumption is to switch from incandescent to fluorescent lighting.
Fluorescent lights are capable of producing the same amount of light as incandescent bulbs while utilizing a significantly reduced amount of electrical power to produce the same amount of light. Accordingly, homes or businesses which convert from incandescent to fluorescent lighting can see significant energy cost savings through such a conversion. Reduced power consumption decreases the demand for power from electric utilities, and thus contributes to environmental conservation by reducing the consumption of fossil fuels used to generate electricity.
Due to the high cost of building electric generating facilities to meet the ever-growing need for electric power, some electric utilities provide incentives for those consumers who convert to energy saving fluorescent lighting. However, due to technical limitations, fluorescent lights previously required bulky starter and ballast circuits for proper operation, and were not usable with standard incandescent light sockets. As technology has advanced, the reduction in size of starter and ballast circuits, and the development of adapters for using fluorescent lights with incandescent bulb sockets, have made fluorescent lighting a viable alternative to the standard incandescent bulb.
As mentioned, adaptors for using fluorescent lights in standard incandescent bulb sockets are known. Prior art fluorescent light adapters typically include a starter and ballast circuit disposed in a housing having a threaded portion sized to fit in an incandescent bulb socket. A fluorescent tube assembly can then be connected to the starter and ballast circuit, thus completing the conversion from incandescent to fluorescent lighting.
One problem commonly associated with converting from incandescent to fluorescent lighting is the cost of the conversion. Fluorescent light bulbs complete with an incandescent adaptor have tended to cost on the order of two to three times (or more) as much as incandescent bulbs. While the operation of a fluorescent bulb in place of an incandescent bulb will generally, over time, more than cover the cost of conversion due to the corresponding energy cost savings, the initial cost of such a conversion often prevents homeowners businesses from performing the conversion project.
One example of a prior art device for use in converting an incandescent lighting fixture to a fluorescent fixture is shown in FIGS. 1 and 3-6. As can be seen in the FIGURES, a prior art fluorescent light conversion assembly includes a fluorescent tube structure 20 having a base 21 and a plurality of electrical connectors 22 disposed on a connector mount 24. The connector mount 24 is disposed on a bottom surface 25 of the tube base 21. The internal structure of the tube base is known and includes the wiring connections between the fluorescent tubes and the electrical connectors 22.
A significant feature of prior art fluorescent tube assemblies is the use of a substantially rectangular, hollow support plug 26 disposed on the base 21 which mates with a corresponding receptacle 42 when the fluorescent tube assembly is connected with a starter and ballast circuit housing 30. The support plug 26 provides the tube assembly with support and structural integrity sufficient to maintain the connection between the fluorescent tube assembly 20 and the housing 30 regardless of the orientation (i.e., horizontal, vertical, etc.) of the fluorescent light conversion assembly 10.
Disposed on the plug 26 are a pair of protruding members 28 which serve as a wattage key, i.e., the size and shape of the members 28 are used to code the wattage of the tube assembly 20, to prevent tube assemblies 20 which have higher power requirements from being used with starter and ballast circuits 30 which do not have sufficient power handling capacity to adequately and safely service such a tube structure.
The circuit housing 30 includes a cover 32 which is conical in shape. A plurality of electrical wires 34 are disposed in the cover for providing the connection between the external power supply and the starter and ballast circuit (not shown). A threaded coupling 36 is provided for use in a standard incandescent light bulb socket. A starter and ballast circuit support cap 38 mates with the cover 32 to form an enclosed chamber 35 to house the starter and ballast circuits (not shown). Snap connector rings 58 and 60 are provided on the starter circuit support cap 38 and the cover 32, respectively, to provide a snap fit between the starter support cap 38 and the cover 32.
The upper surface 39 of the starter circuit support cap 38 includes a relieved portion 40 which serves as a receptacle for the connector mount 24. Optional guide slots 41 may be provided in the relieved portion 40 which mate with guide members disposed on the base 21 to ensure proper orientation of the tube assembly 20 when mating with the starter circuit 30. Within the relieved area 40, a receptacle 42 is formed for receiving the support plug 26.
The relieved area 40 includes a planar surface 43 having formed therein a plurality of connector receptacles 44 for receiving the electrical connectors 22. The receptacle 42 has slots 45 formed in side surfaces thereof for receiving the protruding members 28 formed on the side surfaces of the rectangular plug 26. In addition to signifying wattage of the bulb, the protruding members serve to releasably secure the fluorescent tube assembly 20 to the circuit housing 30.
Referring in particular to FIG. 3, the cover 32 is provided with a plurality of air vents 33 to dissipate excess heat which may be generated by the starter circuit. The receptacle 42 is defined by walls 46 which protrude into the cavity 35 formed when the cover 32 is fitted with the support cap 38. As a result, the usable size of the cavity 35 for housing starter and ballast circuit components is effectively reduced by the size of the receptacle 42. In addition, a plurality of cylindrical housings 48 protrude into the cavity 35 to form the connector receptacles 44 which receive the electrical connectors 22 from the fluorescent tube assembly 20. The housings 48 each include a wire connector hole 50 for accommodating electrical connections between an electrical contact 47 disposed in the housing 48 and the starter and ballast circuit. The wires 34 connect with electrical connectors 52 and 54 disposed on a top portion of the threaded coupling 36.
In the prior art fluorescent light conversion assembly 10, the starter and ballast circuits are typically formed using electronic components disposed on a printed circuit board which is mounted on surface 56 defined by the relieved area 40. As can be seen in FIG. 4, the surface 56 has an irregular shape which necessitates the fabrication of a specialized circuit board. In addition, the extension of the receptacle 42 and the housings 48 into the cavity 35 limit the available space for housing the starter and ballast circuits. As a result, unless the size of the cavity is increased, thereby undesirably increasing the overall size of the starter portion 30, the cavity 35 is only capable of accommodating a small, unsophisticated starter and ballast circuit.
Manufacturing starter and ballast circuits for the prior art device discussed above adds significantly to the overall cost of the fluorescent light assembly due to the specialized manufacturing required to accommodate the unusual shape and size of the cavity 35.
Further, due to the limited amount of space in cavity 35 resulting from the protrusion of walls 46 defining receptacle 42 into the cavity 35, the prior art device 10 is unable to accommodate a high power factor ballast circuit. High power factor ballast circuits, which draw less current than low power factor devices, are fast becoming required equipment in fluorescent lighting devices. However, a high power factor ballast circuit includes significantly more components (capacitors, inductors, resistors, transistors, etc.) than a low power factor ballast circuit. With the lack of available space in the cavity 35 of the prior art device 10, it is impracticable to incorporate a high power factor ballast circuit therein without increasing the size of the cavity 35.
Another disadvantage related to the protrusion of the receptacle 42 into cavity 35 is the effect on heat dissipation and the overall size of the starter portion 30. In the illustrated prior art device, the starter portion 30 is bulky, which prevents the device from being used in certain lamps and fixtures having limited space to accommodate a bulb. This is due in part to the size of the cover 32 which is provided with cooling air vents 33 to dissipate the heat generated by the starter and ballast circuit.
The size of the cover 32 must be large enough to provide a cavity 35 that allows sufficient air circulation therein to ensure proper cooling. The protrusion of the receptacle 42 into cavity 35 prevents the reduction in size of the cover 32, and prevents a corresponding reduction in the overall size of the starter portion 30, due to heat dissipation requirements and the lack of space in the cavity 35 in the prior art device.
Accordingly, there is a need for a fluorescent light adaptor module for use in a standard incandescent light bulb socket which is easier and less costly to manufacture. There is also a need for a module which is capable of accommodating a high power factor ballast circuit without increasing the overall size of the device, as well as a need for device of reduced size yet having sufficient heat dissipation capabilities.